Bernie Sanders and President Barack Obama will sit down on Thursday. (Photo by Win McNamee/Getty Images)

President Barack Obama is expected to take on a tough job on Thursday — trying to ensure that millions of Bernie Sanders supporters begin falling in behind presumptive Democratic presidential nominee Hillary Clinton.

It will be difficult for Clinton to defeat Donald Trump without a large number of the 12 million people who have cast primary votes so far for the independent Vermont senator.

The U.S. started swinging to the right with Ronald Reagan's election to the White House in 1980. But the mix of issues in 2016 are more favorable to Democrats. (Roll Call file photo)

Both Donald Trump and Ted Cruz have glaring weaknesses as presidential nominees, but that’s only the beginning of the GOP's problems. Just as important, the current mix of top issues is simply terrible for Republicans in general and conservatives in particular.

The country moved noticeably to the right starting in the early 1980s with Ronald Reagan and continuing through the presidency of Bill Clinton (“The era of big government is over”) and even the first years of the George W. Bush administration.